Field of the Invention
The present invention relates to a blow-by gas processing circuit for an internal combustion engine, in which a carburetor having an intake passageway extending laterally is connected to one side surface of an internal combustion engine with an insulator member interposed between the carburetor and the one side surface, and an air cleaner placed above the carburetor is connected to an upstream end of the carburetor.
Description of the Related Art
As disclosed in Japanese Patent Application Laid-open No. 3-33417, a generally-used blow-by gas processing circuit for an internal combustion engine conventionally includes: a first blow-by gas lead-out pipe extending out from the internal combustion engine so as to reach a purification completion chamber of an air cleaner; a control valve attached to an intake pipe of the internal combustion engine to which a carburetor is connected, and configured to open in accordance with a rise in boost negative pressure of the internal combustion engine; and a second blow-by gas lead-out pipe extending out from the internal combustion engine to be connected to the control valve.